package com.lantu;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.patchca.background.BackgroundFactory;
import org.patchca.color.ColorFactory;
import org.patchca.color.RandomColorFactory;
import org.patchca.filter.ConfigurableFilterFactory;
import org.patchca.filter.library.AbstractImageOp;
import org.patchca.filter.library.WobbleImageOp;
import org.patchca.font.RandomFontFactory;
import org.patchca.service.Captcha;
import org.patchca.service.ConfigurableCaptchaService;
import org.patchca.text.renderer.BestFitTextRenderer;
import org.patchca.text.renderer.TextRenderer;
import org.patchca.word.RandomWordFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * 验证码生成类
 * 
 * 
 * 
 * 使用开源验证码项目patchca生成
 * 
 * 
 * 
 * 
 * 
 * @author wanghao
 * 
 * @version 1.00 
 */
@WebServlet("/code")
public class ValidationCodeServlet extends HttpServlet {
	private final static Logger logger = LoggerFactory.getLogger(ValidationCodeServlet.class);
	private static final long serialVersionUID = 5126616339795936447L;

	private ConfigurableCaptchaService configurableCaptchaService = null;

	private ColorFactory colorFactory = null;

	private RandomFontFactory fontFactory = null;

	private RandomWordFactory wordFactory = null;

	private TextRenderer textRenderer = null;

	public ValidationCodeServlet() {

		super();

	}

	/**
	 * 
	 * Servlet销毁方法,负责销毁所使用资源. <br>
	 */

	public void destroy() {

		wordFactory = null;

		colorFactory = null;

		fontFactory = null;

		textRenderer = null;

		configurableCaptchaService = null;

		super.destroy(); // Just puts "destroy" string in log

	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)

	throws ServletException, IOException {

		doPost(request, response);

	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)

	throws ServletException, IOException {
		///logger.info("#######requet check code #######");
		response.setContentType("image/png");
        response.setHeader("Cache-Control", "no-cache, no-store");
        response.setHeader("Pragma", "no-cache");
        long time = System.currentTimeMillis();
        response.setDateHeader("Last-Modified", time);
        response.setDateHeader("Date", time);
        response.setDateHeader("Expires", time);
        
		HttpSession session = request.getSession(true);

		OutputStream outputStream = response.getOutputStream();

		// 得到验证码对象,有验证码图片和验证码字符串

		Captcha captcha = configurableCaptchaService.getCaptcha();

		// 取得验证码字符串放入Session

		String validationCode = captcha.getChallenge();

		session.setAttribute("validationCode", validationCode);
		logger.info("sessionid="+session.getId()+","+(String)session.getAttribute("validationCode"));
		// 取得验证码图片并输出

		BufferedImage bufferedImage = captcha.getImage();

		ImageIO.write(bufferedImage, "png", outputStream);

		outputStream.flush();

		outputStream.close();

	}

	/**
	 * 
	 * Servlet初始化方法
	 */

	public void init() throws ServletException {

		configurableCaptchaService = new ConfigurableCaptchaService();

		// 颜色创建工厂,使用一定范围内的随机色

		colorFactory = new RandomColorFactory();

		configurableCaptchaService.setColorFactory(colorFactory);

		// 随机字体生成器

		fontFactory = new RandomFontFactory();

		fontFactory.setMaxSize(32);

		fontFactory.setMinSize(28);

		configurableCaptchaService.setFontFactory(fontFactory);

		// 随机字符生成器,去除掉容易混淆的字母和数字,如o和0等

		wordFactory = new RandomWordFactory();

		wordFactory.setCharacters("abcdefghkmnpqstwxyz1234567890");

		wordFactory.setMaxLength(5);

		wordFactory.setMinLength(4);

		configurableCaptchaService.setWordFactory(wordFactory);

		// 自定义验证码图片背景

		MyCustomBackgroundFactory backgroundFactory = new MyCustomBackgroundFactory();

		configurableCaptchaService.setBackgroundFactory(backgroundFactory);

		// 图片滤镜设置

		ConfigurableFilterFactory filterFactory = new ConfigurableFilterFactory();

		List<BufferedImageOp> filters = new ArrayList<BufferedImageOp>();

		WobbleImageOp wobbleImageOp = new WobbleImageOp();

		wobbleImageOp.setEdgeMode(AbstractImageOp.EDGE_MIRROR);

		wobbleImageOp.setxAmplitude(2.0);

		wobbleImageOp.setyAmplitude(1.0);

		filters.add(wobbleImageOp);

		filterFactory.setFilters(filters);

		configurableCaptchaService.setFilterFactory(filterFactory);

		// 文字渲染器设置

		textRenderer = new BestFitTextRenderer();

		textRenderer.setBottomMargin(3);

		textRenderer.setTopMargin(3);

		configurableCaptchaService.setTextRenderer(textRenderer);

		// 验证码图片的大小

		configurableCaptchaService.setWidth(82);

		configurableCaptchaService.setHeight(32);

	}

	/**
	 * 
	 * 自定义验证码图片背景,主要画一些噪点和干扰线
	 */

	private class MyCustomBackgroundFactory implements BackgroundFactory {

		private Random random = new Random();

		public void fillBackground(BufferedImage image) {

			Graphics graphics = image.getGraphics();

			// 验证码图片的宽高

			int imgWidth = image.getWidth();

			int imgHeight = image.getHeight();

			// 填充为白色背景

			graphics.setColor(Color.WHITE);

			graphics.fillRect(0, 0, imgWidth, imgHeight);

			// 画100个噪点(颜色及位置随机)

			for (int i = 0; i < 100; i++) {

				// 随机颜色

				int rInt = random.nextInt(255);

				int gInt = random.nextInt(255);

				int bInt = random.nextInt(255);

				graphics.setColor(new Color(rInt, gInt, bInt));

				// 随机位置

				int xInt = random.nextInt(imgWidth - 3);

				int yInt = random.nextInt(imgHeight - 2);

				// 随机旋转角度

				int sAngleInt = random.nextInt(360);

				int eAngleInt = random.nextInt(360);

				// 随机大小

				int wInt = random.nextInt(6);

				int hInt = random.nextInt(6);

				graphics.fillArc(xInt, yInt, wInt, hInt, sAngleInt, eAngleInt);

				// 画5条干扰线

				if (i % 20 == 0) {

					int xInt2 = random.nextInt(imgWidth);

					int yInt2 = random.nextInt(imgHeight);

					graphics.drawLine(xInt, yInt, xInt2, yInt2);

				}

			}

		}

	}

}